From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752958AbcHXDoP (ORCPT ); Tue, 23 Aug 2016 23:44:15 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:36362 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199AbcHXDoN (ORCPT ); Tue, 23 Aug 2016 23:44:13 -0400 MIME-Version: 1.0 In-Reply-To: References: <1471942474-1854-1-git-send-email-alexander.shishkin@linux.intel.com> <87shtvl8c5.fsf@ashishki-desk.ger.corp.intel.com> From: Alexander Shishkin Date: Wed, 24 Aug 2016 06:44:12 +0300 X-Google-Sender-Auth: Z4y28UoSp-I7ZFipUcu0KpUUrOc Message-ID: Subject: Re: [PATCH 0/3] perf, bts: Fallout from the fuzzer for perf/urgent To: Vince Weaver Cc: Alexander Shishkin , Peter Zijlstra , Ingo Molnar , Linux Kernel Mailing List , Stephane Eranian , Arnaldo Carvalho de Melo Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks! I'll get back to you with something better. On 23 August 2016 at 23:55, Vince Weaver wrote: > On Tue, 23 Aug 2016, Alexander Shishkin wrote: > >> Vince Weaver writes: >> >> > On Tue, 23 Aug 2016, Alexander Shishkin wrote: >> > >> >> Recently Vince has reported warnings and panics coming from the >> >> general direction of AUX tracing. I found two bugs which manifest >> >> similarly, one in intel_bts driver and one in AUX unmapping path. >> >> >> >> Both are triggered by racing SET_OUTPUT against mmap_close while >> >> running AUX tracing. I have a test case that set fire to the kernel >> >> within a few seconds by doing this, which I can share if anyone >> >> cares. >> > >> > I've applied these and am fuzzing on my Haswell machine and I'm getting >> > lots and lots of >> > >> > [ 945.536374] Dazed and confused, but trying to continue >> > [ 945.542391] Uhhuh. NMI received for unknown reason 21 on CPU 2. >> > [ 945.549360] Do you have a strange power saving mode enabled? >> > [ 945.556701] Dazed and confused, but trying to continue >> > [ 945.563643] Uhhuh. NMI received for unknown reason 31 on CPU 2. >> > [ 945.571379] Do you have a strange power saving mode enabled? >> > [ 945.578754] Dazed and confused, but trying to continue >> > [ 945.630889] Uhhuh. NMI received for unknown reason 31 on CPU 2. >> > [ 945.638141] Do you have a strange power saving mode enabled? >> > [ 945.645523] Dazed and confused, but trying to continue >> > >> > messages that I wasn't getting before. Of course, I updated from -rc2 to >> > -rc3 before applying the patch so it could also be related to that too, I >> > can try backing out the patches and see if it still happens. >> >> Uhhuh, that's not cool, let me look some more. But it should stop dying >> on bts/aux stuff at least. > > Just wanted to say that when I backed out these patches the NMI errors > went away, so they do seem to be a result of this patch series. > > Vince